High frequency power amplifier apparatus and power amplifier module use the same

ABSTRACT

In a high frequency power amplifier apparatus of the present invention, ground terminal ( 17   e ) of automatic power control circuit ( 17 ) is connected to ground terminal ( 13   c ) of power amplifier ( 13 ) through inductive reactance element ( 18 ) for preventing frequency supplied from power amplifier ( 13 ). Noise occurring from automatic power control circuit ( 17 ) can be prevented from disturbing power amplifier ( 13 ).

THIS APPLICATION IS A U.S. NATIONAL PHASE APPLICATION OF PCTINTERNATIONAL APPLICATION PCT/JP02/12118.

TECHNICAL FIELD

The present invention relates to a high frequency power amplifierapparatus used in a handy phone or an information communicationterminal, and a power amplifier module using the high frequency poweramplifier apparatus.

BACKGROUND ART

A conventional high frequency power amplifier apparatus is described. Asshown in FIG. 4, the conventional high frequency power amplifierapparatus has the following elements:

-   -   input terminal 1;    -   power amplifier 2 for receiving a signal that has been fed into        input terminal 1;    -   directional coupler 3 for receiving an output from power        amplifier 2;    -   output terminal 4 for receiving an output from directional        coupler 3; and    -   automatic power control circuit 5 of which input portion 5 a is        connected to coupling output terminal 3 a of directional coupler        3 and output portion 5 b is connected to power control terminal        2 a of power amplifier 2.

Ground terminal 5 c of automatic power control circuit 5 is connected toground terminal 2 b of power amplifier 2 through conductor 6 and thengrounded.

Noise level is required to be low in a receiving band of an apparatusemploying the high frequency power amplifier apparatus, but a noisecharacteristic of the receiving band is degraded in the conventionalcircuitry for the following reason. Since ground terminal 5 c isconnected to ground terminal 2 b through conductor 6 and then groundedin this circuitry, noise generated by a signal from power amplifier 2via automatic power control circuit 5 comes into power amplifier 2through conductor 6 and ground terminal 2 b and comes out of poweramplifier 2 again, thereby degrading the noise characteristic.

DISCLOSURE OF THE INVENTION

The present invention provides a high frequency power amplifierapparatus having the following elements:

an input terminal;

a power amplifier for receiving a signal supplied from the inputterminal;

a directional coupler for receiving an output from the power amplifier;

an output terminal for receiving an output from the directional coupler;and

an automatic power control circuit of which input portion is connectedto a coupling output terminal of the directional coupler and outputportion is connected to a power control terminal of the power amplifier.A ground terminal of the automatic power control circuit is connected toa ground terminal of the power amplifier through an inductive reactanceelement for preventing frequency supplied from the power amplifier.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a high frequency power amplifier apparatusin accordance with exemplary embodiment 1 of the present invention.

FIG. 2 is a sectional view of a high frequency power amplifier module inaccordance with exemplary embodiment 2 of the present invention.

FIG. 3 is a plan view of the high frequency power amplifier module inaccordance with exemplary embodiment 2 of the present invention.

FIG. 4 is a block diagram of a conventional high frequency poweramplifier apparatus.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Exemplary embodiments of the present invention will be describedhereinafter with reference to FIG. 1 to FIG. 3.

(Exemplary Embodiment 1)

FIG. 1 is a circuit diagram of a high frequency power amplifierapparatus in accordance with exemplary embodiment 1. In FIG. 1, the highfrequency power amplifier apparatus has the following elements:

input terminal 11;

input matching circuit 12 connected to input terminal 11;

power amplifier 13 connected to an output portion of input matchingcircuit 12;

output matching circuit 14 connected to an output portion of poweramplifier 13;

directional coupler 15 connected to an output portion of output matchingcircuit 14;

output terminal 16 connected to an output portion of directional coupler15; and

automatic power control circuit 17 of which input portion 17 a isconnected to coupling output terminal 15 a of directional coupler 15 andoutput portion 17 b is connected to power control terminal 13 a of poweramplifier 13.

Control terminal 19 for controlling amplification degree of poweramplifier 13 from the outside is connected to input portion 17 c ofautomatic power control circuit 17. Control terminal 20 controls turningon or off of a power supply of power amplifier 13 from the outside, isconnected to input portion 17 d of automatic power control circuit 17,and is connected to power supply control terminal 13 b of poweramplifier 13 via automatic power control circuit 17.

Ground terminal 17 e of automatic power control circuit 17 is connectedto ground terminal 13 c of power amplifier 13 through inductivereactance element 18. Inductive reactance element 18 prevents noisesupplied from automatic power control circuit 17. Frequency of the noisecomes from power amplifier 13 to automatic power control circuit 17.

In the high frequency power amplifier apparatus, a technologyspecialized in a high frequency circuit is modularized, and the poweramplifier and its peripheral circuit that are used in a handy phone oran information communication terminal requiring an engineer specializedin the high frequency circuit are modularized and unified. The poweramplifier and its peripheral circuit for the handy phone or theinformation communication terminal can be therefore designed withoutrequiring the engineer specialized in the high frequency circuit.

In this circuitry, an additional ground terminal of automatic powercontrol circuit 17 is not required, and the ground terminal of poweramplifier 13 can be shared when the power amplifier and its peripheralcircuit are modularized. The number of the ground terminals can bereduced.

Since ground terminal 17 e of automatic power control circuit 17 isconnected to ground terminal 13 c of power amplifier 13 throughinductive reactance element 18 for preventing the frequency suppliedfrom power amplifier 13, noise is not transmitted to power amplifier 13from automatic power control circuit 17 through the ground terminaldifferently from the prior art, and power amplifier 13 is not disturbed.

The noise of the high frequency power amplifier apparatus does not causeincrease of the noise level of a receiving band in a receiving system,and thus the receiving sensitivity characteristic can be improved.

Inductive reactance element 18 can employ a winding coil, a coil formedin a print pattern, or a transmission line. In embodiment 1, atransmission line of ¼ wavelength of a frequency supplied from poweramplifier 13 is employed. Thanks to the ¼ wavelength, the amplitudelevel of a noise signal is zero just at ground terminal 13 c of poweramplifier 13, and noise supplied from automatic power control circuit 17does not disturb power amplifier 13. Length of the transmission line maybe set at an odd number times larger than the ¼ wavelength of adisturbing frequency.

The coil formed in the print pattern may be used as inductive reactanceelement 18. The coil is formed of a pattern inductor, so that the coilcan be thinned and prevents the noise supplied from the automatic powercontrol circuit from disturbing the power amplifier. In this case, aneffect substantially similar to the transmission line is produced.

The winding coil may be used as inductive reactance element 18. In thiscase, a parallel resonant circuit can be formed of a capacitance betweenwindings of the coil. Therefore, by adjusting the inductance of thecoil, the resonance frequency can be matched with the disturbingfrequency and the disturbing noise can be accurately and efficientlyremoved.

Input matching circuit 12 is used, so that input impedance is set at 50Ω, and a signal fed from input terminal 11 can be efficientlytransmitted to power amplifier 13. Output matching circuit 14 is alsodisposed, so that an output of power amplifier 13 can be efficientlytransmitted to directional coupler 15. Loss of a signal supplied frompower amplifier 13 can be therefore reduced. In other words, less powerconsumption is required for the same output.

Directional coupler 15 employs intaglio printing, so that a Q value canbe increased compared with etching. Loss of the signal supplied frompower amplifier 13 can be therefore reduced. In other words, less powerconsumption is required for the same output.

The degree of coupling of directional coupler 15 is set between 10 and20 dB, and level of a transmission signal outputted from coupling outputterminal 15 a of directional coupler 15 is set so that input portion 17a of automatic power control circuit 17 receives a signal having anappropriate level. An output portion of directional coupler 15 isconnected to output terminal 16 and outputs the transmission signal.

Control terminal 19 can control the amplification degree of poweramplifier 13, so that an appropriate output can be obtained depending oncommunication distance and the power consumption can be reduced. Powersupply control terminal 20 can control turning on or off of the powersupply of power amplifier 13, so that power amplifier 13 can be operatedonly in transmitting the signal to reduce the power consumption.

(Exemplary Embodiment 2)

FIG. 2 is a sectional view of a high frequency power amplifier module inaccordance with exemplary embodiment 2 of the present invention. FIG. 3is a plan view of the high frequency power amplifier module. In FIG. 2and FIG. 3, inorganic glass 32 is laminated on the upper surface ofalumina substrate 31, and power amplifier 13 is mounted to asubstantially central part on inorganic glass 32.

Input circuits 12 or the like including components are disposed on bakedsubstrate 34 on one side 33 of power amplifier 13. Output matchingcircuits 14 or the like including components are disposed on bakedsubstrate 36 on the other side 35 of power amplifier 13. Thesecomponents are covered with metallic shield case 37. Therefore, noise isnot transmitted from an automatic power control circuit to the poweramplifier through the ground terminal in the power amplifier module, andthus the noise does not disturb the power amplifier. This structureprevents the noise of the power amplifier from increasing the noiselevel of a receiving band and reducing the receiving sensitivity.

Alumina substrate 31 is mainly formed of alumina and has a relativedielectric constant of 9 to 11. Substrates 34 and 36 have a meltingpoint temperature lower than that of alumina substrate 31. Substrates 34and 36 are low-temperature baked substrates capable of being laminatedlike a green sheet, so called low temperature co-fired ceramics (LTCC)substrates. Low-temperature baked substrates 34 and 36 include built-inreceiving components 45, and components 45 form parts of input matchingcircuit 12, output matching circuit 14, and automatic power controlcircuit 17.

Surface mounting components 38 form parts of input matching circuit 12,output matching circuit 14, and automatic power control circuit 17.Directional coupler 15 is formed in intaglio printing method, and has aQ value higher than that in a printing method using etching technology.Loss of the signal supplied from the power amplifier can be thereforereduced. In other words, less power consumption is required for the sameoutput.

Printing pattern 39 is used for heat dissipation in embodiment 2.Printing pattern 39 having low thermal resistance disposed on inorganicglass 32 for supporting power amplifier 13 is used for efficientlydissipating heat generated in power amplifier 13, and promotes thermaldiffusion to alumina substrate 31. Thermal via holes 40 are also formedunder power amplifier 13, thereby increasing a heat dissipation effectof power amplifier 13. The heat of power amplifier 13 can be releasedout of alumina substrate 31 through thermal via holes 40, so thatefficiency of power amplifier 13 is improved.

Thermal via holes 40 have a diameter of 0.1 to 0.5 mm. The diameter islimited not to exceed the thickness of alumina substrate 31, therebypreventing decrease of the strength of alumina substrate 31.

In this state, inductive reactance element 18 is constituted by a seriescircuit of ground wire 41 of power amplifier 13, first via hole 42forming the ground terminal of power amplifier 13, transmission line 43,and second via hole 44 forming the ground terminal of automatic powercontrol circuit 17. Inorganic glass 32 prevents the short circuit inalumina substrate 31 and low-temperature baked substrates 34, 36.

This circuitry can provide the high frequency power amplifier modulehaving the heat dissipation effect and low receiving noise level.

As discussed above, in the present invention, the ground terminal of theautomatic power control circuit is connected to the ground terminal ofthe power amplifier through the inductive reactance element forpreventing frequency supplied from the power amplifier. The noise is nottherefore transmitted from the automatic power control circuit to thepower amplifier and does not disturb the power amplifier.

The noise of the high frequency power amplifier module is prevented fromincreasing the noise level in the receiving band, and the receivingsensitivity characteristic can be improved.

INDUSTRIAL APPLICABILITY

The present invention relates to a high frequency power amplifierapparatus used in a handy phone or an information communicationterminal, and provides the high frequency power amplifier module inwhich noise occurring via an automatic power control circuit does notdisturb a power amplifier.

1. A high frequency power amplifier apparatus comprising: an inputterminal; a power amplifier for receiving a signal supplied from saidinput terminal; a directional coupler for receiving an output from saidpower amplifier; an output terminal for receiving an output from saiddirectional coupler; and an automatic power control circuit, an inputportion of said automatic power control circuit being connected to acoupling output terminal of said directional coupler, an output portionof said automatic power control circuit being connected to a powercontrol terminal of said power amplifier, wherein a ground terminal ofsaid automatic power control circuit is connected to a ground terminalof said power amplifier through an inductive reactance element forpreventing frequency supplied from said power amplifier.
 2. A highfrequency power amplifier apparatus according to claim 1, wherein theinductive reactance element comprises a transmission line having alength substantially equal to one of ¼ wavelength of a frequencysupplied from said power amplifier and an odd number times larger thanthe ¼ wavelength.
 3. A high frequency power amplifier apparatusaccording to claim 1, wherein the inductive reactance element comprisesa pattern inductor.
 4. A high frequency power amplifier apparatusaccording to claim 1, wherein the inductive reactance element comprisesa winding coil.
 5. A high frequency power amplifier apparatus accordingto claim 1, wherein said directional coupler is formed by intaglioprinting.
 6. A high frequency power amplifier apparatus according toclaim 1, wherein an input matching circuit is disposed between saidinput terminal and said power amplifier.
 7. A high frequency poweramplifier apparatus according to claim 1, wherein an output matchingcircuit is disposed between said power amplifier and said directionalcoupler.
 8. A high frequency power amplifier apparatus according toclaim 1, wherein said power control terminal is connected to saidautomatic power control circuit, and an amplification degree of saidpower amplifier is controlled with an output of said automatic powercontrol circuit.
 9. A high frequency power amplifier apparatus accordingto claim 1, wherein said power control terminal is connected to saidautomatic power control circuit, and turning on or off of a power supplyof said power amplifier is controlled with an output of said automaticpower control circuit.
 10. A power amplifier module including a highfrequency power amplifier apparatus in one multilayer substrate, saidhigh frequency power amplifier module comprising: an input terminal; apower amplifier for receiving a signal supplied from the input terminal;a directional coupler for receiving an output from the power amplifier;an output terminal for receiving an output from the directional coupler;and an automatic power control circuit, an input portion of theautomatic power control circuit being connected to a coupling outputterminal of the directional coupler, an output portion of the automaticpower control circuit being connected to a power control terminal of thepower amplifier, wherein a ground terminal of the automatic powercontrol circuit is connected to a ground terminal of the power amplifierthrough an inductive reactance element for preventing frequency suppliedfrom the power amplifier.
 11. A power amplifier module according toclaim 10, wherein a component mounting surface of the multilayersubstrate is covered with a shield case.
 12. A power amplifier moduleaccording to claim 10, wherein the power amplifier is mounted to theupper surface of an alumina substrate via inorganic glass, and heat ofthe power amplifier is released to the back surface of the aluminasubstrate from the power amplifier through a thermal via hole.
 13. Apower amplifier module according to claim 12, wherein a printing patternis disposed on the inorganic glass for supporting the power amplifier.14. A power amplifier module according to claim 12, wherein diameter ofthe thermal via hole is set to be smaller than thickness of themultilayer substrate.
 15. A power amplifier module according to claim12, wherein a low-temperature baked substrate is disposed on the uppersurface of the inorganic glass, and the automatic power control circuitis disposed on the low-temperature baked substrate.
 16. A poweramplifier module according to claim 12, wherein the directional coupleris disposed on the upper surface of the alumina substrate and is formedby intaglio printing.